RETIREMENT PLANS - Net Periodic Pension Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Pension plan
Earnings (cost) components:
Interest cost	$ (78)	$ (73)
Expected return on plan assets	138	188
Net amortization and deferral	(12)	(18)
Total net periodic pension earnings	48	97
SERP
Earnings (cost) components:
Interest cost	(46)	(41)
Net amortization and deferral	(29)	(31)
Total net periodic pension earnings	$ (75)	$ (72)